While watching news, you hear about a place, of which you had never heard earlier. You want to know more about the place and you want to locate it on the map. Which of the following is/are required for you to be able to locate the place on the map?
- (a)Only latitude of the place
- (b)Only longitude of the place
- (c)Both longitude and latitude of the place
- (d)Latitude, longitude and altitude of the place
Correct — C, Both longitude and latitude of the place. A point on the Earth's surface is fixed by two coordinates — latitude (angular distance north or south of the Equator) and longitude (angular distance east or west of the Prime Meridian). Either one alone defines only a line of points, so both are needed to pinpoint a place on a map.
- (a)Only latitude of the place — Latitude alone fixes only the north–south position — every point on that parallel of latitude shares it, so you still need longitude to locate the place.
- (b)Only longitude of the place — Longitude alone fixes only the east–west position along a meridian; without latitude the place cannot be pinned down.
- (d)Latitude, longitude and altitude of the place — Altitude gives height above sea level and is not needed to locate a place on a two-dimensional map; latitude and longitude are sufficient.
The system of latitude and longitude forms a grid (the graticule) covering the Earth. Latitude runs from 0° at the Equator to 90° at the poles; longitude runs from 0° at the Prime Meridian to 180° east and west. The intersection of a stated latitude and longitude uniquely identifies a location.
The question tests whether a candidate realises that a single coordinate is not enough. Latitude alone traces a full circle around the globe; longitude alone traces a meridian. Only the pair fixes a point. Altitude is a third dimension useful for elevation, not for locating a place on a flat map.
- Latitude measures position north or south of the Equator (0°–90°).
- Longitude measures position east or west of the Prime Meridian (0°–180°).
- A place is uniquely located only where a given latitude and longitude cross.
- Altitude is height above sea level — not needed to fix a position on a map.
Only both coordinates together locate a place; altitude is not required on a map.
- Thinking one coordinate is enough to locate a point.
- Adding altitude as if it were needed to find a place on a map.
A reasoning question on the geographic coordinate system — both latitude and longitude are needed.
No directly related past PYQ was found.
- practice — not a real PYQ
The angular distance of a place measured east or west of the Prime Meridian is its
- (a)latitude
- (b)longitude
- (c)altitude
- (d)azimuth
Answer(b) longitude — measured east or west of the Prime Meridian.
- practice — not a real PYQ
The 0° line of latitude is known as the
- (a)Prime Meridian
- (b)Equator
- (c)Tropic of Cancer
- (d)International Date Line
Answer(b) Equator — the 0° parallel of latitude.